diff ratios

[willet]

Hi folks,just joined up to the board.
I own a 320i E30 Beemer,but the rear end has packed up.I have the back axle from a 1.8i E30 but I'm not sure how far apart the ratios are from the 2litre and the 1800.The manual I have doesn't cover the 1800cc models,(if it even fits-I havn't checked underneath yet!).Does anyone know if the final drive would alter a huge amount by fitting the 1.8 backend?
Any advice is most welcome!Thanks.

 

[KC Ron Carter]

Hmm,

Both are 4 cylinders so they should be the same.

There is a tag on the aft face of the differential with the ratio on it.

Check them out.

If it has a white 4 inch letter "S" painted on it it is a limited slip differential.

Later,

 

[Rukus]

1.8 ? You mean 318i?

Final drive on e30 318i: 3.64:1 prior to 11/83, 3.91:1 after 11/83

3.64:1 most 2002s, all 2-liter 320i's, 1.8L 320iA's
3.90:1 1976 49-state 2002, 1.8L 5-speed 320i's


So if the information i gathered is correct, then yes it looks like a diff from an early 318i (if thats what you mean) will fit your car. all you need to do it swap rear covers from what i understand.

 

[willet]

Yes,its the diff from an early 318i I have,I think it was a B reg.
So all being well,I shouldn't have any difference at cruising speed?

Thanks very much lads!

 

[Rukus]

Search the forums here for a thread on differentials from before. I did an AWESOME write up on different ratios and how they affect your car not too long ago. It'll be located in this part of the forums.